How Do I Check a Server Connect Field String Exists?

I have a server connect called get_payment.

I then want to display a string like this:

<p dmx-text="get_payment.data.payment.description.HAS_A_VALUE() ? get_payment.data.payment.description:'A Message'"></p>

I want .HAS_A_VALUE() to be false if:

1. get_payment returns no record
2. get_payment returns a record but the description field is null
3. get_payment returns a record but the description field is an empty string

How do I do that in Wappler?